


Werewolf Anatomy and Physiology

by TamerOfPickles



Series: Teen Wolf Kink Bingo - 2018 [3]
Category: Teen Wolf (TV)
Genre: Accidental Knotting, Anal Sex, Bondage, Bottom Mason Hewitt, First Time Bottoming, M/M, Science Kink, Teen Wolf Kink Bingo, Teen Wolf Kink Bingo - 2018, Top Liam Dunbar, Werewolf Biology, Werewolf Genitalia
Language: English
Status: Completed
Published: 2018-06-26
Updated: 2018-06-26
Packaged: 2019-05-28 20:41:46
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,549
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15057416
Author URL: https://archiveofourown.org/users/TamerOfPickles/pseuds/TamerOfPickles
Summary: After Mason discovers that his best friend is a werewolf, he gets curious about whether certain stories he read were true. Liam wants to find out as well, so they agree to try an experiment.





	Werewolf Anatomy and Physiology

**Author's Note:**

> For the square Tied to the bed.
> 
> Because they never showed her on screen or even gave her a name, I felt free to make Liam's mother into Liam's father.

Liam turned toward the wolf and roared, causing it to turn and flee. He revelled in his triumph for a moment before remembering Mason. He paused to brace himself for the moment he had been putting off for too long. “There’s something I gotta tell you.”

Mason’s eyes were wide with delight rather than the fear or anger that Liam had anticipated. “You’re a werewolf!”

After they had went to Liam’s place and called Mason’s parents to let them know that he’d be spending the night there, they resumed their conversation.

“So, you’re not mad?” Liam sat down on his bed and gave Mason his best puppy dog face. Mason suspected that Liam wasn’t even conscious that he was using it.

In any case, it wasn’t necessary. “No. I understand what it’s like to have a secret that you worry will change things when it comes out.” Mason put his hand on Liam’s shoulder with a look of somber reassurance. He held out as long as he could until the questions burst out. “Were you bitten or born? That’s a thing, right? I’m not sure what in those books is true. It was bitten, right? A couple months before those bone guys attacked? What were those guys? I noticed you started acting strangely around then. Who bit you? It has to be an alpha, right? This is so cool. It had to be Scott. He seems like the leader of the group. Is everyone a werewolf? Does that make it a pack? Wait, do I have to become a werewolf now that you’ve told me? I don’t know how I feel about that. It seems like a big deal. What’s a full moon like? Is …”

Liam had to resort to covering Mason’s mouth with his hand to get a word in. “You don’t have to become a werewolf. Actually, Scott’s reluctant to bite anyone. He only bit me to keep me from falling off the roof.” Somehow Mason’s eyes got wider. “We’ll come back to that. Only Scott and I are werewolves. Oh, and that new guy, Theo. He wants to join the pack. There were others, but they left. Malia’s a werecoyote, which is more or less the same thing. Kira’s a kitsune, which is some sort of Japanese fox thing. Stiles was also one, but ‘He got better.’ I’m not sure what that means. They don’t like to talk about it. Lydia’s a banshee, which has something to do with screaming and dead people. Full moons are … wild. I’m not sure how else to describe them. I’m still learning how to control myself during them. Two months ago, I spent the night running around town naked until Scott and Stiles caught me and brought me home.”

Mason couldn’t let this pass without comment. Pulling Liam’s hand down, he asked, “Seriously? That was you? I need to take down those pictures from my blog.”

“You have a blog?”

“Yeah. I didn’t mention it because you seemed annoyed when I brought up supernatural stuff.”

“Sorry about that.”

“It’s okay. Does that mean that you go streaking every month?”

“No. Sometimes I can keep it under control. Scott and Stiles chain me up until they can tell whether it will be a good night or a bad night.” Mason raised an eyebrow at this. “Really. I can show you.” Liam got up and opened a duffle bag inside his closet. Inside were a variety of chains, cuffs, and padlocks that would allow them to restrain someone regardless of the circumstances. All were quite sturdy, which made Mason wonder exactly how strong werewolves were.

“Kinky.”

Liam laughed and pointed to his bed. “It’s even worse. We installed rings into the sides of my bed to attach the chains when we have the house to ourselves. Otherwise, they usually tie me up to a tree."

“When you change into a werewolf, what exactly happens?"

“Well, you saw the claws, the teeth, the brow, the sideburns. My eyes glow yellow because I'm a beta. Scott's are red. Malia gets blue eyes. They won't tell me what that means, but her father and cousin (who are werewolves) have them too. Maybe it's a family thing."

“Anything else?"

“I don't know. More hair?"

“Oh." Mason was disappointed. “I had read about other changes." He blushed as he searched for a euphemism. “Down below."

“Down belo-? Oh!" Now it was Liam's turn to blush. “I've never thought to check."

“But you said you've gone streaking while changed."

“It's like a dream when I lose control. I just remember bits and pieces. Running free through the woods. The cool night air. A million smells I never noticed before. The taste of hot blood."

“Blood?" Mason froze.

“Squirrel blood. I went hunting one night."

Mason was relieved. “And Scott's never mentioned anything?"

“Scott tells me stuff when it occurs to him, but he's too easily distracted to do any real training. Stiles helps now that he's no longer jealous, but they're both still new to this, too. I think there's a lot of stuff that they don't know.”

They took a video game break to adjust to what they had just discussed. After fifteen minutes, Liam paused the game and set down his controller. “This is freaking me out. I need to know if being a werewolf messes with my junk.”

Mason stood up and started to leave. “Sorry about that. I’ll let you get on with it.”

Liam grabbed Mason’s arm. “Can you help me? I think I’ll need some help processing this if I do find a surprise.”

Mason’s heart raced. He’d been curious about this ever since he found that hint of unusual anatomy. Shit, Can werewolves hear heartbeats? He tried to be nonchalant. “Ah, sure, dude. It’s my fault for putting the thought in your head.” Mason got up to turn off the console and TV as Liam pulled off his socks and shoes and tossed them into a corner. The screen went black just in time for Mason to see the reflection of Liam pulling his shirt over his head. Mason paused to appreciate Liam’s supernaturally enhanced abs, but when Liam’s head was freed from his shirt, they made eye contact. Both blushed and looked away.

Liam got up from the bed and started rummaging through the bag of bondage gear Scott and Stiles had given him. “I don’t think I’ll do anything that will make these necessary, but better safe than sorry.” He pulled out four sets of heavy chains attached to padded metal cuffs and handed them to Mason. “Can you attach these to the rings on the side of the bed?” Liam watched the first one to make sure he could figure it out before turning to the corner and grabbing the button of his pants. He paused to take a moment to calm his nerves. He had undressed in front other guys countless times during lacrosse, but then everyone was making a point not to look at each other while Mason would be . . . what exactly had he asked Mason to do? Rather than dwell on that thought, Liam pulled his pants and underwear down and stepped out of them in one swift motion.

Liam turned around to see that Mason had been staring at his ass and was now getting a good look his dick. Liam absentmindedly adjusted himself while Mason mumbled “Sorry” and busied himself with the final restraint.

Liam laughed nervously to break the tension. “You were only doing what I asked you to do.” Liam crawled onto his bed and began closing the cuffs around his ankles. He attached his far hand and handed the key to Mason to do the last one. Once Liam was secure, he began to test his bonds. As Mason walked to the foot of the bed, he was mesmerized by Liam’s flexing muscles. It felt weird to finally be able to look at them without trying to hide it.

By the time Mason was standing between his feet, Liam was satisfied that the restraints would hold. “Ready?” Mason could only manage to swallow nervously and nod. Liam rolled his eyes back and willed himself to transform with a growl. Mason stared at Liam’s groin and was surprised by the speed. The top of his penis fused with the skin above it. His scrotum retracted to hold his balls close to his body. His pubic hair was replaced with short, dense hairs covering the entire region with fur.

“Woah!” Mason hadn’t believed that it would be true.

“What?” Liam looked down. “Dude! Where’d my dick go?” Liam pulled against his chains as he tried to sit up.

“Liam! It’s okay. It’s right here.” Mason reached down and pressed his hand along the length of Liam’s furry bump. The sensation was enough to stop Liam’s panic. When Mason reached the top, he began to search for the opening with his finger. “I just need to coax it out.” The tip of his finger slipped into the sheath and teased the end of Liam’s cock. Liam gasped in surprise and pleasure as his cock began to slip out of its sheath. “That’s different,” Mason whispered.

“What?” Liam opened his eyes again and looked down. His mushroom head had been replaced with a pointed tip that expanded smoothly into the shaft without a distinct ridge separating it into parts. Mason began to squeeze Liam between his thumb and index finger. “Does it feel any different?”

“I didn’t touch it before you turned, so I don’t know. We’ll have to do this again while you are human. For science.”

Liam nodded sagely. “Yes, for science.”

Mason gently tugged on Liam’s cock to bring more of it out of the sheath. Liam began to buck his hips impatiently. Mason took the hint, firmly wrapped his hand around Liam, and began to stroke. Liam’s panting began to include a soft growling. All of this combined to make Mason’s pants uncomfortable. He tried to discretely shift himself by moving into different positions, but it wasn’t much help.

He also wasn’t as discrete as he had hoped. Liam gave him a cocky grin. “You can get more comfortable if you want.”

Somehow Mason still managed to blush despite being in the middle of giving a chained up werewolf a handjob. He had to tell himself that, unlike the gym showers, it was entirely to appropriate to get hard while jerking off a guy in his bedroom. He was still nervous about being naked in front of his friend for the first time, but he figured it couldn’t be worse than trying to find a comfortable way to keep his dick in his pants. He sat back and reached behind his head to pull his green v-neck off of himself. After he tossed it to the floor, he paused self-consciously as he realized that Liam was examining his body. He was surprised to see Liam look . . . appreciative of what he saw. He didn’t have the supernaturally-enhanced athlete’s build of his friend, but working out together had given him a lean, toned physique.

He undid his belt keenly aware of Liam’s interested gaze. He deliberately took his time unzipping his fly in order to tease his friend. When Mason tucked his thumbs into the sides of his underwear, Liam was biting his lip in anticipation. After a breath to calm his nerves, Mason lifted himself off his heels and pulled his pants down far enough to release his dick. He had a self-conscious urge to fluff himself, but he was already rock hard and worried that it would be enough to push him over the edge.

Liam stared at Mason’s cock in fascination. He had seen other guys naked in the locker room, but he always averted his eyes, and in any case they were never in such a powerful state. To his surprise, he found that he didn’t mind seeing Mason naked. In fact, he kind of liked it.

Mason was relieved when Liam responded positively. He was always self-conscious next to his more athletic and supernaturally enhanced friend.

He got back onto the bed and gave Liam’s new dick a few prods. It seemed fully hard, so he wasn’t sure what else he could do. He pulled it up and away from Liam’s body so that the boy could get a better look at himself. “What do you think of the change?”

Liam took a good look, but he found himself struggling not to look off to the side at Mason’s dick. “I was shocked at first, but now I like it.”

Mason let it fall back down. “I guess we’ve answered our question.”

Liam tilted his head to the side. “Well... we haven’t checked whether it functions differently.”

Mason nodded. “Yes. We’ve covered anatomy, but not physiology.” Liam was confused. “Nevermind.” Mason grabbed Liam’s cock and leaned forward so that it was just a few inches from his face. “What is the reaction when I do this?” Mason wrapped his lips around the tip of Liam’s cock and went down a couple of inches before sliding back up in order to get Liam’s answer.

Liam’s head had rolled back while Mason had teased his dick. “That was promising, but I think we should check again.”

“Yes. Replication is essential for science.” Mason went down again. This time he used his tongue to find Liam’s most sensitive spots and slowly worked his way down the shaft. At this point, he had decided to forget about the scientific pretext. He wasn’t experienced enough to swallow the whole thing, but judging by the moans, growls, and whines coming from the head of the bed, he doubted Liam was unhappy about it.

As Liam’s body began to push his lips upwards in an attempt to get deeper into Mason’s mouth, Liam let out a breathless “Wait!”

Mason immediately sat up and crawled up closer to Liam. “Did I hurt you?”

Liam shook his head. “No. It felt good. Really good.” Liam looked down as he gathered the courage to continue. “I was just wondering, and I completely understand if you don’t want to because it’s kind of a big deal and you’ve done so much already…”

“Just tell me what you want, Liam.”

“Can I fuck you?”

Mason’s eyes went wide at the question. He reached down and touched Liam’s dick in order to get a better sense of just what he would be in for. It wasn’t small by any measure, but it wasn’t so big that they’d make porn videos about it wrecking people’s asses. Mason had never had anything more than a couple of fingers up there, but perhaps he could manage with a lot of lube and a lot of patience (as all of his research had told him). “We can try. I’ll need to steal your dads’ lube.” Mason hurried off to retrieve it from the special drawer they had discovered a few months ago when they were bored and left by themselves.

Liam waited spread eagle, chained to the bed, with his dick sticking up in the air. He laughed at the idea of how he’d explain this if anyone walked in on him, but he trusted Mason enough not to worry about it.

Mason came running back with the bottle and plopped down on the bed next to Liam. As he began to apply the lube to his hole, he turned to Liam. “You have to promise me that you’ll let me do this at my own speed.”

“I’ll try.” Mason gave Liam a displeased look. “I’ve never done this before. I don’t know how I’ll react. I promise that if I feel myself losing control, I’ll warn you.”

“I guess that will have to do.” Mason moved so that he straddled Liam’s cock while facing him. He was satisfied that he was ready, so he poured a healthy amount of lube on Liam and spread it along his length. He could feel Liam tense up in response to the stimulation as he fought to keep himself from fucking Mason’s hand. Mason gave Liam a wink to acknowledge his appreciation for his restraint.

Mason lined the dick up with his hole and pressed back until they were just touching. He made sure to breathe deeply as it slowly slid inside him. He wouldn’t say it felt good yet, but it also didn’t feel bad. Which he supposed counted as good. Before he knew it, he was sitting on Liam’s hips. Looking up, he saw Liam giving him a toothy grin.

“How does my dick feel?”

“Full. And maybe something that’s the start of feeling good. How about you?”

“You’re so warm and wrapped all around me. It’s so much better than my hand.”

Mason continued his work getting used to the dick. With the help of some more lube, he was soon able to ride Liam at a faster, less controlled pace. He also figured out how to get it to rub him in just the right spot.

Liam began to grunt everytime Mason came down on him. “I don’t know how much longer I can hold back.”

Mason was feeling too good to stop now. “It’s okay. I’m ready.”

Freed to fuck, Liam began to push in and out of Mason. He didn’t have much mobility or leverage while restrained, but in his transformed state he was able to use every millimeter available to him and maintain an impressive pace.

Mason responded to every thrust with moaned feedback to guide Liam. By the time Liam finally lost control of himself, he instinctively knew how Mason wanted it. That was good because Mason no longer had the presence of mind to speak coherently. Neither was in a state to notice one additional change until it was too late.

Mason felt something large push into and then pull him back down as Liam tried to pull back out. No longer able to thrust, Liam switched to lateral motions that rolled his cock inside Mason. Soon Liam was pulling at his restraints as he tried to lean forward, filling his room with a deafening roar, and filling Mason with his hot werewolf cum. That was too much for Mason as well, and the first wave of his cum was flying into Liam’s hair. The ones that followed left a trail down Liam’s face and chest until it met where Mason’s softening cock rested on Liam’s abs.

Mason dropped down so that he was lying on top of Liam. Liam, no longer transformed, was the first to be able to speak. “I’d call that a successful experiment.”

An exhausted Mason responded, “Definitely. That was … intense.” He then tried to roll off of Liam but found that he couldn’t. “That’s different.”

“Shit. This can’t be permanent, can it?”

Mason thought about it for a moment before concluding, “I don’t think so. Otherwise werewolves would be walking around attached at the hips. You might want to call Scott just to be safe.”

The blood rushing to Liam’s face unfortunately did not ease their predicament. “You’re right. Can you still untie me?”

With a stretch, Mason could reach the key on the nightstand and unlock Liam’s wrists. As he undid the ankle restraints, Liam was able to get his phone.

Scott answered just before it would have gone to voicemail. “What’s up Liam? Is it an emergency?”

“Sort of.”

“Can it wait? I’m in the middle of something right now.”

“Is there anything about being a werewolf that you didn’t tell me? Like sex stuff.”

“Oh.” Scott’s annoyance disappeared. “Liam, did you discover your knot?” In the background he could hear Stiles break out into laughter.

“Is that what it’s called? It isn’t permanent, is it? Can you come over and talk me through it?”

“No, it’s not permanent. Unfortunately, I can’t come over right now.”

Stiles grabbed the phone from Scott. “Hey, Liam. Don’t worry. It will go away in about thirty minutes. And sorry for laughing before. I wasn’t laughing at you. I was laughing because we’re similarly indisposed right now.”

“Oh. Wow.”

“Did someone help you discover this?”

“Yeah. Mason was curious about werewolves and things moved further than we expected.”

“I hope he enjoyed himself.”

“Yeah. He did.”

“Great. We’ll talk about this in the morning. Night Liam.”

“Night Stiles.”

Before he could tell Mason what they had said, Liam heard a car pull into the driveway. “It’s my dads! Hide.” With some awkwardness, they managed to pull the covers back onto the bed and turn out the lights before Liam heard the door to the garage open. He followed the sound of their footsteps as they moved through the house up to their bedroom. They made a stop to check on Liam, but moved on without saying anything. Liam sighed with relief that they didn’t notice anything unusual. He was about to say something when he heard a pair of steps coming back.

“Liam. Are you awake?”

Liam feigned having just woken up. “Yes, Dad.”

“Did you take something from our room?”

Liam had forgotten about the lube. “Oh. Sorry about that.”

“We’ll have a talk about this tomorrow.”

“Okay.”

“And you, too, Mason.”

From below the covers, Mason sheepishly replied. “Yes, sir.”

“Good night boys.”


End file.
